Compare (a) the numer of atoms and (b) the number of grams present in 1.00 mole of helium and 1.00 mole of argon

For a: The number of atoms of both the gases remains the same.

For b: The number of grams of 1 mole of argon is more than 1 mole of helium.

Explanation:

We are given 1 mole of each helium and argon gas. To calculate the number of atoms of each gas, we use mole concept.

According to mole concept:

1 mole of an element contains number of atoms.  

So, 1 mole of helium gas will contain atoms.

And, 1 mole of argon gas will contain atoms.

Hence, both the gases have same number of atoms.

To calculate the number of moles, we use the formula:

Molar mass = 4 g/mol

Number of moles = 1 mole

Putting the values in above equation, we get:  

Molar mass = 39.95 g/mol

Number of moles = 1 mole

Putting the values in above equation, we get:  

Difference in mass of argon and helium = (39.95 - 4)g = 35.95g

Hence, mass of argon is more than mass of helium by 35.95 grams.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3